Etchant composition for etching silicon germanium film and method of manufacturing integrated circuit device by using the same

ABSTRACT

An etchant composition for etching a silicon germanium film includes, based on a total weight of the etchant composition, about 5 wt% to about 14 wt% of an oxidant, about 0.01 wt% to about 5 wt% of a fluorine compound, about 0.01 wt% to about 5 wt% of an amine compound, about 0.01 wt% to about 1 wt% of an alcohol compound having a hydrophilic head and a hydrophobic tail, about 60 wt% to about 90 wt% of an organic solvent, and a balance of water. A method of manufacturing an integrated circuit device includes: forming, on a substrate, a structure in which a plurality of silicon films and a plurality of silicon germanium films are alternately stacked; and selectively removing the plurality of silicon germanium films by using the etchant composition.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. §119 toKorean Patent Application No. 10-2022-0025510, filed on Feb. 25, 2022,in the Korean Intellectual Property Office, the disclosure of which isincorporated by reference herein in its entirety.

BACKGROUND 1. Field

Embodiments relate to an etchant composition and a method ofmanufacturing an integrated circuit device by using the etchantcomposition, and more particularly, to an etchant composition forselectively etching a silicon germanium film, and a method ofmanufacturing an integrated circuit device by using the etchantcomposition.

2. Description of the Related Art

Due to the advancement of electronics technology, semiconductor deviceshave been rapidly down-scaled in recent years, and to overcome a limitin improvement of the degree of integration of 2-dimensionalsemiconductor devices, interest has developed in a 3-dimensionalsemiconductor memory device in which memory cells are 3-dimensionallyarranged.

SUMMARY

An embodiment is directed to an etchant composition for etching asilicon germanium film, the etchant composition including, based on atotal weight of the etchant composition, about 5 % by weight (wt%) toabout 14 wt% of an oxidant, about 0.01 wt% to about 5 wt% of a fluorinecompound, about 0.01 wt% to about 5 wt% of an amine compound, about 0.01wt% to about 1 wt% of an alcohol compound having a hydrophilic head anda hydrophobic tail, about 60 wt% to about 90 wt% of an organic solvent,and a balance of water.

An embodiment is directed to a method of manufacturing an integratedcircuit device, the method including: forming, on a substrate, astructure in which a plurality of silicon films and a plurality ofsilicon germanium films are alternately stacked. The method furtherincludes: selectively removing the plurality of silicon germanium filmsfrom among the plurality of silicon films and the plurality of silicongermanium films by using an etchant composition. The etchant compositionincludes, based on a total weight of the etchant composition, about 5wt% to about 14 wt% of an oxidant, about 0.01 wt% to about 5 wt% of afluorine compound, about 0.01 wt% to about 5 wt% of an amine compound,about 0.01 wt% to about 1 wt% of an alcohol compound having ahydrophilic head and a hydrophobic tail, about 60 wt% to about 90 wt% ofan organic solvent, and a balance of water.

An embodiment is directed to a method of manufacturing an integratedcircuit device, the method including: forming, on a substrate, a moldlayer in which a plurality of first silicon films and a plurality ofsilicon germanium films are alternately stacked. The method furtherincludes: forming an insulating structure to cover a sidewall of themold layer. The method further includes: forming a mold pattern byforming a trench through anisotropic etching of the plurality of firstsilicon films and the plurality of silicon germanium films, the moldpattern including respective remaining portions of the plurality offirst silicon films and the plurality of silicon germanium films, whichdefine the trench. The method further includes: forming a plurality ofair gaps by selectively removing, from the mold pattern, the pluralityof silicon germanium films from among the plurality of first siliconfilms and the plurality of silicon germanium films through the trench byusing an etchant composition, the plurality of air gaps exposing theplurality of first silicon films and the insulating structure. Theetchant composition includes, based on a total weight of the etchantcomposition, about 5 wt% to about 14 wt% of an oxidant, about 0.01 wt%to about 5 wt% of a fluorine compound, about 0.01 wt% to about 5 wt% ofan amine compound, about 0.01 wt% to about 1 wt% of an alcohol compoundhaving a hydrophilic head and a hydrophobic tail, about 60 wt% to about90 wt% of an organic solvent, and a balance of water.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail example embodiments with reference to the attached drawings inwhich:

FIG. 1 is a flowchart illustrating a method of manufacturing anintegrated circuit device, according to an example embodiment; and

FIGS. 2A to 8C are diagrams illustrating a method of manufacturing anintegrated circuit device according to an example embodiment, and inparticular, FIGS. 2A, 3A, 4A, 6A, 7A, and 8A are each a plan viewillustrating the method of manufacturing an integrated circuit device,FIG. 2B, FIG. 3B, FIGS. 4B and 5 , FIG. 6B, and FIG. 8B are enlargedcross-sectional views of cross-sectional areas, taken along lines A-A′of FIG. 2A, FIG. 3A, FIG. 4A, FIG. 6A, and FIG. 8A, respectively, andFIGS. 7B and 8C are enlarged cross-sectional views taken along linesB-B′ of FIGS. 7A and 8A, respectively.

DETAILED DESCRIPTION

An etchant composition according to an example embodiment includes anoxidant, a fluorine compound, an amine compound, an alcohol compound, anorganic solvent, and water.

In an example embodiment, based on a total weight of the etchantcomposition, the oxidant may be present in an amount of about 5 wt% toabout 14 wt%, the fluorine compound may be present in an amount of about0.01 wt% to about 5 wt%, the amine compound may be present in an amountof about 0.01 wt% to about 5 wt%, the alcohol compound may be present inan amount of about 0.01 wt% to about 1 wt%, and the organic solvent maybe present in an amount of about 60 wt% to about 90 wt%. Water may bepresent in the remaining amount excluding the respective amounts of theoxidant, the fluorine compound, the amine compound, the alcoholcompound, and the organic solvent.

In an example embodiment, the oxidant may include a C1-C6 carboxylicacid compound, a C1-C6 peroxyacid compound, or a combination thereof. Inan example embodiment, the oxidant may include a C1-C3 carboxylic acidcompound, a C1-C3 peroxyacid compound, or a combination thereof. Forexample, the oxidant may include peracetic acid, performic acid, aceticacid, formic acid, propionic acid, or a combination thereof.

In an example embodiment, the fluorine compound may include hydrofluoricacid (HF), sodium fluoride (NaF), potassium fluoride (KF), aluminumfluoride (AlF₂), lithium fluoride (LiF₄), calcium fluoride (CaF₃),sodium hydrogen hexafluoride (NaHF₆), ammonium fluoride (NH₄F), ammoniumdifluoride (NH₄HF₂), tetramethylammonium fluoride ((CH₃)₄NF), potassiumbifluoride (KHF₂), fluoroboric acid (HBF₄), ammonium tetrafluoroborate(NH₄BF₄), potassium fluoroborate (KBF₄), hexafluorosilicic acid(H₂SiF₆), or a combination thereof.

In an example embodiment, the amine compound may include a C1-C8aliphatic amine compound, a 5- to 8-membered cyclic amine, or acombination thereof.

In example embodiments, the amine compound may include at least onematerial selected from ethylamine, isopropylamine, dimethylbutylamine,diisopropylethylamine, and an aliphatic polyamine. The aliphaticpolyamine may include an amine compound having at least two aminogroups. The aliphatic polyamine may include a polyamine having a linearor branched hydrocarbon group. For example, the aliphatic polyamine mayinclude ethylenediamine, dimethylaminoethylmethylamine,1,2-propylenediamine, 1,3-propylenediamine, 1,4-butanediamine,1,3-diaminopentane, hexamethylenediamine,2-methyl-pentamethylenediamine, or a combination thereof.

In an example embodiment, the amine compound may include a cyclic amine.The cyclic amine may include pyrrole, oxazole, imidazole,methylimidazole, pyrazole, triazole, aminotriazole, tetrazole,5-aminotetrazole, methyltetrazole, piperazine, methylpiperazine,hydroxyethylpiperazine, pyrrolidine, alloxan, or a combination thereof.

In an example embodiment, the alcohol compound may have a hydrophilichead and a hydrophobic tail. In an example embodiment, the alcoholcompound may be a polyhydric alcohol having at least two hydroxyl groupsas the hydrophilic head, and may have a C8-C16 normal alkyl group as thehydrophobic tail.

For example, the alcohol compound may include a diol having thehydrophobic tail or a triol having the hydrophobic tail. For example,the alcohol compound may include a C8-C16 alkane-1,2-diol. For example,the alkane-1,2-diol may include 1,2-octanediol, 1,2-decanediol,1,2-dodecanediol, 1,2-tetradecanediol, or the like.

The alkane-1,2-diol may have a structure in which hydroxyl groupsconstituting the hydrophilic head are respectively bonded at positions 1and 2 of an 8- to 16-carbon chain constituting the hydrophobic tail.Therefore, the hydrophobic tail may be adsorbed on a hydrophobic surfacenot intended to be etched, e.g., a surface of an Si film, and thus, mayprotect the Si film. In addition, the hydrophilic head may improvesolubility of the alcohol compound in the etchant composition.

In an example embodiment, the organic solvent may include a C1-C5carboxylic acid compound. In an example embodiment, the organic solventmay include acetic acid, methyl acetate, ethyl acetate, propyl acetate,isopropyl acetate, or a combination thereof. For example, the organicsolvent may include acetic acid.

In an example embodiment, in the etchant composition, when the oxidantincludes peroxyacid, the etchant composition may further include about0.01 wt% to about 5 wt% of a catalyst, based on the total weight of theetchant composition. In an example embodiment, a peroxyacid solution maybe obtained through an equilibrium reaction between hydrogen peroxideand a carboxylic acid compound in the presence of the catalyst. Forexample, the catalyst may include sulfuric acid or methanesulfonic acid.

In a structure in which a silicon (Si) film and a silicon germanium(SiGe) film are simultaneously exposed, the etchant compositionaccording to an example embodiment may selectively remove the SiGe filmbetween the Si film and the SiGe film with relatively high etchselectivity.

In particular, as dynamic random-access memory (DRAM) devices have beenrapidly down-scaled, to overcome a limit in improvement in the degree ofintegration of existing 2-dimensional DRAM devices, 3-dimensional DRAM,in which memory cells are 3-dimensionally arranged, has been developed.In 3-dimensional DRAM, a single-crystal silicon film (single-crystal Sifilm), which facilitates control of leakage current, may be formed as achannel region. To form the single-crystal Si film, a multi-stackstructure, in which a plurality of Si films and a plurality of SiGefilms are alternately stacked, may be formed on a substrate by anepitaxial growth process. When a Ge concentration in each of theplurality of SiGe films included in the multi-stack structure isrelatively high, there is concern that dislocation due to latticemismatch is generated in the plurality of Si films. To remove thepossibility of the generation of dislocation in the plurality of Sifilms, it may be considered to reduce a germanium content (Ge content)in each of the plurality of SiGe films included in the multi-stackstructure. For example, in each of the plurality of SiGe films includedin the multi-stack structure, the Ge content may be selected from arange of about 10 atomic % (at%) to about 20 at%. A surface state of anSiGe film having a relatively low Ge content as such may be almostsimilar to a surface state of an Si film. In a structure including an Sifilm and also including an SiGe film that has a relatively low Gecontent, the etchant composition according to an example embodiment maybe used to selectively remove the SiGe film at high etch selectivity tothe Si film, even when the Si film and the SiGe film have surface statesthat are very similar to each other.

In an example embodiment, the oxidant and water included in the etchantcomposition may act to oxidize the Ge element included in the SiGe film.In an example embodiment, the Ge element included in the SiGe film maybe oxidized by the oxidant or water in the etchant composition, and as aresult, metagermanic acid (H₂GeO₃), which is a soluble material, may begenerated. As the Ge element is oxidized at an exposed surface of theSiGe film, the Si element having imperfect bonding at the exposedsurface of the SiGe film may be removed through oxidation by the oxidantincluded in the etchant composition and etching by the fluorine compoundincluded in the etchant composition.

The amine compound included in the etchant composition may function asan etch booster for accelerating the etching of an oxidation resultingproduct (Ge oxide) of the Ge element, which is oxidized by the oxidantor water, and an oxidation resulting product (Si oxide) of the Sielement, which is oxidized by the oxidant. Therefore, the amine compoundmay increase the etch selectivity of the plurality of SiGe films withrespect to the plurality of Si films included in the multi-stackstructure. The amine compound may be adsorbed on Ge oxide and Si oxide,which are formed during the process of etching by the etchantcomposition. Ge oxide and Si oxide, on which the amine compound isadsorbed, may easily and quickly react with fluorine ions. Therefore,the amine compound may help to remove Ge oxide and Si oxide, which areformed during the process of etching by the etchant composition.

The alcohol compound included in the etchant composition according to anexample embodiment may protect the Si film while the SiGe film isoxidized by the oxidant and water and etched by the fluorine compound,thereby helping to prevent the Si film from being etched, e.g., toreduce an etch rate thereof. For example, when the alcohol compoundincludes an alkane-1,2-diol, an end of a carbon chain constituting ahydrophobic tail of the alkane-1,2-diol may be adsorbed on a hydrophobicsurface of the Si film by hydrophobic interaction, thereby helping toprotecting the Si film. Therefore, the etch selectivity of the SiGe filmwith respect to the Si film may be increased by the alcohol compound.

In a multi-stack structure in which a plurality of Si films and aplurality of SiGe films are alternately stacked, and in which a Gecontent in each of the plurality of SiGe films is about 15 at%, inselectively removing the plurality of SiGe films by using the etchantcomposition according to an example embodiment, the etch selectivity ofthe SiGe film with respect to the Si film may be 100 or more.

For example, when an Si film and an SiGe film having a Ge content ofabout 15 at% are each etched under the same conditions by using theetchant composition according to an example embodiment, an etch rate ofthe Si film may be less than 1 Å/min, and an etch rate of the SiGe filmmay be greater than 100 Å/min.

As such, by using the etchant composition according to an exampleembodiment, even when a Ge content in an SiGe film is relatively low, ahigh etch selectivity of the SiGe film with respect to an Si film may beobtained.

FIG. 1 is a flowchart illustrating a method of manufacturing anintegrated circuit device, according to an example embodiment.

In a process P10 of FIG. 1 , a structure, in which a plurality of Sifilms and a plurality of SiGe films are alternately stacked, may beformed on a substrate.

The substrate may include a semiconductor substrate. In an exampleembodiment, the semiconductor substrate may include an elementalsemiconductor, such as Si or Ge, or a compound semiconductor, such assilicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs),or indium phosphide (InP).

To form the structure, an epitaxial growth process may be performed. Inthe structure, each of the plurality of Si films may include asingle-crystal Si film. Each of the plurality of SiGe films may have aGe content selected from a range of about 10 at% to about 20 at%. Inexample embodiments, in each of the plurality of SiGe films, the Gecontent may be selected from a range of about 12 at% to about 18 at% ora range of about 14 at% to about 16 at%. For example, in each of theplurality of SiGe films, the Ge content may be about 15 at%.

In a process P20 of FIG. 1 , the plurality of SiGe films (from among theplurality of Si films and the plurality of SiGe films) may beselectively removed by using an etchant composition according to anexample embodiment. A detailed configuration of the etchant compositionis as described above.

In an example embodiment, in the etchant composition, the oxidant mayinclude peracetic acid, performic acid, acetic acid, formic acid,propionic acid, or a combination thereof, the fluorine compound mayinclude hydrofluoric acid (HF), the amine compound may include a C1-C8aliphatic polyamine, the alcohol compound may include a C8-C16alkane-1,2-diol, and the organic solvent may include acetic acid. Theetchant composition may further include about 0.01 % by weight (wt%) toabout 5 wt% of a catalyst, based on a total weight of the etchantcomposition. The catalyst may include sulfuric acid or methanesulfonicacid.

FIGS. 2A to 8C are diagrams illustrating a method of manufacturing anintegrated circuit device 100 (see FIGS. 8A, 8B, and 8C) according to anexample embodiment.

More specifically, each of FIGS. 2A, 3A, 4A, 6A, 7A, and 8A is a planview illustrating the method of manufacturing the integrated circuitdevice 100. FIG. 2B, FIG. 3B, FIGS. 4B and 5 , FIG. 6B, and FIG. 8B areenlarged cross-sectional views of cross-sectional areas taken alonglines A-A′ of FIG. 2A, FIG. 3A, FIG. 4A, FIG. 6A, and FIG. 8A,respectively. FIGS. 7B and 8C are enlarged cross-sectional views takenalong lines B-B′ of FIGS. 7A and 8A, respectively.

Referring to FIGS. 2A and 2B, a lower insulating film 104 may be formedon a main surface 102M of a substrate 102. A mold layer ML, including aplurality of semiconductor films 110 and a plurality of sacrificialfilms SL, may be formed on the lower insulating film 104. Among theplurality of semiconductor films 110, the upper surface of thesemiconductor film 110 that is uppermost and farthest from the substrate102 may correspond to the uppermost surface of the mold layer ML.

The substrate 102 may include an elemental semiconductor, such as Si orGe, or a compound semiconductor, such as SiGe, SiC, GaAs, InAs, InGaAs,or InP.

The lower insulating film 104 may include a silicon oxide film, asilicon nitride film, a silicon oxynitride film, or a combinationthereof.

The mold layer ML may have a structure in which the plurality ofsemiconductor films 110 and the plurality of sacrificial films SL arealternately stacked. Each of the plurality of semiconductor films 110and the plurality of sacrificial films SL, which constitute the moldlayer ML, may be formed by an epitaxial growth process. In an exampleembodiment, each of the plurality of semiconductor films 110 may includea single-crystal Si film, and each of the plurality of sacrificial filmsSL may include an SiGe film.

Each of the plurality of semiconductor films 110 may include asingle-crystal Si film, whereby leakage current may be easily controlledin a plurality of channel regions CH (see FIG. 8C) respectively formedfrom the plurality of semiconductor films 110.

In forming each of the plurality of semiconductor films 110 and theplurality of sacrificial films SL, which constitute the mold layer ML,by an epitaxial growth process, to prevent dislocation due to latticemismatch in the plurality of semiconductor films 110 each including asingle-crystal Si film, each of the plurality of sacrificial films SLmay have a relatively low Ge content. To this end, the SiGe filmconstituting the plurality of sacrificial films SL may have a Ge contentselected from a range of about 10 at% to about 20 at%. In an exampleembodiment, the SiGe film constituting the plurality of sacrificialfilms SL may have a Ge content selected from a range of about 12 at% toabout 18 at% or a range of about 14 at% to about 16 at%. For example,the SiGe film constituting the plurality of sacrificial films SL mayhave a Ge content of about 15 at%.

The mold layer ML may be partially removed, such that the mold layer MLremains only in a memory cell array area MCA.

Next, an insulating structure 116 may be formed around the memory cellarray area MCA to cover the sidewall of the mold layer ML.

The insulating structure 116 may include a silicon nitride film 116A anda silicon oxide film 116B. The silicon nitride film 116A may contact thesidewall of each of the plurality of semiconductor films 110 and theplurality of sacrificial films SL, which constitute the mold layer ML,and the upper surface of the lower insulating film 104. The siliconoxide film 116B may be arranged on the silicon nitride film 116A tocover the mold layer ML and the substrate 102.

In other implementations, a configuration of the insulating structure116 including various constituent materials and having various stackstructures may be formed.

Referring to FIGS. 3A and 3B, an upper insulating film 120 may be formedon the mold layer ML.

In an example embodiment, the upper insulating film 120 may include asilicon oxide film, a silicon nitride film, a silicon oxynitride film,or a combination thereof.

A mask pattern M1 having a plurality of openings OP1 may be formed onthe upper insulating film 120. The upper insulating film 120 may beexposed by the plurality of openings OP1 of the mask pattern M1.

The mask pattern M1 may include a silicon nitride film. To form the maskpattern M1, a photolithography process may be used.

Referring to FIGS. 4A and 4B, in a resulting product of FIGS. 3A and 3B,the upper insulating film 120 and the mold layer ML may beanisotropically etched through the plurality of openings OP1 by usingthe mask pattern M1 as an etch mask, thereby forming a mold pattern MPincluding a plurality of first trenches TR1, which extend lengthwise ina first horizontal direction (X direction) through the upper insulatingfilm 120 and the mold layer ML, and a plurality of line areas LA, whichextend lengthwise in the first horizontal direction (X direction).

Thus, the mold pattern MP may include respective remaining portions ofthe plurality of semiconductor films 110 and the plurality ofsacrificial films SL.

After the mold pattern MP is formed, the lower insulating film 104 maybe exposed by the plurality of first trenches TR1. The plurality offirst trenches TR1 do not pass through the lower insulating film 104,and thus, the substrate 102 may not be exposed by the plurality of firsttrenches TR1. While an etching process for forming the mold pattern MPis performed, a height of the mask pattern M1 used as an etch mask maybe reduced.

The plurality of first trenches TR1 may each have a line shape extendinglengthwise in the first horizontal direction (X direction). Theplurality of first trenches TR1 may be arranged apart from each other inthe first horizontal direction (X direction) and a second horizontaldirection (Y direction). Respective widths of the plurality of channelregions CH (see FIG. 8C) in the second horizontal direction (Ydirection) may be determined by the plurality of first trenches TR1, theplurality of channel regions CH being respectively formed from theplurality of semiconductor films 110.

Referring to FIG. 5 , the plurality of sacrificial films SL may beremoved from a resulting product of FIGS. 4A and 4B through theplurality of first trenches TR1, thereby forming a plurality of air gapsAG, which expose portions of respective surfaces of the plurality ofsemiconductor films 110 and the silicon nitride film 116A. The pluralityof air gaps AG may be connected to a first trench TR1.

To remove the plurality of sacrificial films SL, an etchant compositionaccording to an example embodiment may be applied to the mold pattern MPthrough the plurality of first trenches TR1. A detailed configuration ofthe etchant composition according to an example embodiment is describedabove. By applying the etchant composition to the mold pattern MP, theplurality of sacrificial films SL from among the plurality ofsemiconductor films 110 and the plurality of sacrificial films SL may beselectively removed.

In an example embodiment, in the etchant composition used to selectivelyremove the plurality of sacrificial films SL, the oxidant may includeperacetic acid, performic acid, acetic acid, formic acid, propionicacid, or a combination thereof, the fluorine compound may includehydrofluoric acid (HF), the amine compound may include a C1-C8 aliphaticpolyamine, the alcohol compound may include a C8-C16 alkane-1,2-diol,and the organic solvent may include acetic acid. The etchant compositionmay further include about 0.01 wt% to about 5 wt% of a catalyst, basedon a total weight of the etchant composition. The catalyst may includesulfuric acid or methanesulfonic acid.

In a structure in which the Si film, the SiGe film, and the siliconnitride film are simultaneously exposed and the Ge content in each ofthe plurality of SiGe films is about 15 at%, in selectively removing theplurality of SiGe films by using the etchant composition according to anexample embodiment, the etch selectivity of the SiGe film with respectto the Si film may be 100 or more, and the etch selectivity of the SiGefilm with respect to the silicon nitride film may be 50 or more. Assuch, by using the etchant composition according to an exampleembodiment, even when the Ge content in the SiGe film is relatively low,a high etch selectivity of the SiGe film with respect to each of the Sifilm and the silicon nitride film may be obtained.

Referring to FIGS. 6A and 6B, a process of removing the mask pattern M1from a resulting product of FIG. 5 and a process of filling theplurality of air gaps AG respectively with a plurality of intermediateinsulating films 124 may be performed.

The plurality of intermediate insulating films 124 may each include asilicon oxide film, a silicon nitride film, a silicon oxynitride film, acarbon-containing silicon oxide film, a carbon-containing siliconnitride film, a carbon-containing silicon oxynitride film, or acombination thereof. In an example embodiment, to form the plurality ofintermediate insulating films 124, an insulating film may be formed tofill the air gap AG between the plurality of semiconductor films 110 byan atomic layer deposition (ALD) process, followed by removingunnecessary portions of the insulating film, thereby leaving theplurality of intermediate insulating films 124 between the plurality ofsemiconductor films 110 arranged in a vertical direction (Z direction).

Next, a gate insulating film 132 may be formed to conformally cover thesidewall of each of the plurality of semiconductor films 110 and thesidewall of each of the plurality of intermediate insulating films 124,which are exposed by the plurality of first trenches TR1, followed byforming a gate line 134 on the gate insulating film 132 to conformallycover the gate insulating film 132 in the plurality of first trenchesTR1, and then, respective portions of the gate insulating film 132 andthe gate line 134 may be removed such that the upper surface of theupper insulating film 120 is exposed and the gate insulating film 132 isexposed at the bottom surface of each of the plurality of first trenchesTR1. In an example embodiment, to form the gate insulating film 132 anda plurality of gate lines 134, an ALD process may be used.

Next, a buried insulating film 136 may be formed on the gate line 134 tofill the plurality of first trenches TR1. The upper surface of theburied insulating film 136 may be planarized to extend on the same planeas the upper surface of the upper insulating film 120.

The gate insulating film 132 may include a stack structure of aninterfacial layer and a high-k film. The interfacial layer may include alow-k material film having a permittivity of about 9 or less, e.g., asilicon oxide film, a silicon oxynitride film, or a combination thereof.In an example embodiment, the interfacial layer may be omitted. Thehigh-k film may include a material having a greater dielectric constantthan a silicon oxide film. For example, the high-k film may have adielectric constant of about 10 to about 25. The high-k film may includehafnium oxide, hafnium silicon oxide, zirconium oxide, zirconium siliconoxide, or a combination thereof.

The gate line 134 may include a doped semiconductor, a metal, aconductive metal nitride, a conductive metal carbide, or a combinationthereof. The metal may be selected from Ti, W, Ru, Nb, Mo, Hf, Ni, Co,Pt, Yb, Tb, Dy, Er, and Pd. The conductive metal nitride may be selectedfrom TiN and TaN. The conductive metal carbide may include TiAlC. In anexample embodiment, the gate line 134 may include a stack structure of aconductive barrier film and a metal film. For example, the conductivebarrier film may include TiN or TaN, and the metal film may include W.

The buried insulating film 136 may include a silicon oxide film, asilicon nitride film, a silicon oxynitride film, or a combinationthereof.

Referring to FIGS. 7A and 7B, a mask pattern (not shown) may be formedon a resulting product of FIGS. 6A and 6B, followed by removingunnecessary portions of the gate line 134 and the buried insulating film136 by using the mask pattern as an etch mask, thereby leaving the gateline 134 and the buried insulating film 136, which cover both sidewallsof each of the plurality of semiconductor films 110 in the secondhorizontal direction (Y direction) in respective portions of theplurality of semiconductor films 110. A portion of the semiconductorfilm 110, which is covered with the gate line 134, may include thechannel region CH (see FIG. 8C).

Next, a plurality of vertical insulating patterns 140 may be formed torespectively fill remaining spaces inside the plurality of firsttrenches TR1. Each of the plurality of vertical insulating patterns 140may cover both sidewalls of each of the gate line 134 and the buriedinsulating film 136 in each of the plurality of first trenches TR1. Eachof the plurality of vertical insulating patterns 140 may includeportions surrounded by the gate insulating film 132 in each of theplurality of first trenches TR1. The plurality of vertical insulatingpatterns 140 may each include a silicon oxide film, a silicon nitridefilm, a silicon oxynitride film, or a combination thereof.

Next, referring to FIG. 7A, a plurality of second trenches TR2 (whichare arranged apart from the plurality of first trenches TR1 on bothsides of each of the plurality of first trenches TR1 in the firsthorizontal direction (X direction) and extend lengthwise in the secondhorizontal direction (Y direction)) may be formed, followed by providinga plurality of spaces to expose respective portions of the plurality ofsemiconductor films 110 by removing respective portions of the pluralityof intermediate insulating films 124, which are exposed by the pluralityof second trenches TR2. Then, the plurality of semiconductor films 110may be doped with impurities through the plurality of spaces, therebyforming a first source/drain region (not shown) in each of the pluralityof semiconductor films 110. Next, a portion of each of the plurality ofspaces may be filled with a conductive material, e.g., a metal, therebyforming a bit line (not shown) in contact with the first source/drainregion. Each of the plurality of bit lines may be formed to beconnectable only to the plurality of semiconductor films 110 located atone horizontal level over the substrate 102. After the plurality of bitlines are formed, the plurality of second trenches TR2 may be filledwith a bit line filling insulating film 160.

Each of the bit line and the bit line filling insulating film 160 mayextend lengthwise in the second horizontal direction (Y direction). Inan example embodiment, the bit line may include doped polysilicon, ametal, a conductive metal nitride, a metal silicide, or a combinationthereof. The metal silicide may include tungsten silicide, cobaltsilicide, or titanium silicide. The bit line filling insulating film 160may include a silicon oxide film, a silicon nitride film, a siliconoxynitride film, or a combination thereof.

Referring to FIGS. 8A, 8B, and 8C, in a resulting product of FIGS. 7Aand 7B, portions of the plurality of semiconductor films 110 may berespectively substituted with a plurality of capacitors 170. To thisend, a plurality of third trenches TR3, which expose the substrate 102,may be formed by removing a portion of each of the upper insulating film120, the plurality of semiconductor films 110, the plurality ofintermediate insulating films 124, and the lower insulating film 104from an area DL marked by a dashed line in FIGS. 7A and 7B, andrespective widths of the plurality of semiconductor films 110 in thefirst horizontal direction (X direction) may be reduced by removingrespective portions of the plurality of semiconductor films 110, whichare exposed at inner sidewalls of the plurality of third trenches TR3.As a result, a plurality of indent regions IND may be formed between thelower insulating film 104 and the intermediate insulating film 124 at alowermost level, between the plurality of intermediate insulating films124, and between the intermediate insulating film 124 at an uppermostlevel and the upper insulating film 120, the plurality of indent regionsIND respectively exposing portions of the plurality of semiconductorfilms 110, which have reduced widths.

In addition, referring to FIG. 8A, in portions of the plurality of thirdtrenches TR3, which overlap the plurality of first trenches TR1,respective widths of the plurality of third trenches TR3 in the firsthorizontal direction (X direction) may be increased by removing portionsof the plurality of vertical insulating patterns 140 and portions of theplurality of gate insulating films 132, which are exposed by theplurality of third trenches TR3.

A second source/drain region SD2 (see FIG. 8C) may be formed by doping aportion of each of the plurality of semiconductor films 110, which areexposed by the plurality of indent regions IND, with impurities. Aportion of each of the plurality of semiconductor films 110, excludingthe first source/drain region (not shown) and the second source/drainregion SD2, may correspond to the channel region CH.

The plurality of capacitors 170 may be respectively formed in theplurality of indent regions IND. In an example embodiment, referring toFIG. 8C, to form the plurality of capacitors 170, a plurality of firstelectrode layers 172 may be formed first to conformally cover respectiveexposed surfaces of the intermediate insulating film 124 and theplurality of semiconductor films 110, which are exposed inside theplurality of indent regions IND. Each of the plurality of firstelectrode layers 172 may contact the second source/drain region SD2formed in each of the plurality of semiconductor films 110. Next, adielectric film 174 may be formed to conformally cover surfaces exposedby the plurality of third trenches TR3. The dielectric film 174 mayconformally cover respective surfaces of the plurality of firstelectrode layers 172, a surface of each intermediate insulating film124, respective surfaces of the plurality of upper insulating films 120,and a surface of the substrate 102, which are exposed by the pluralityof third trenches TR3, the surface of the substrate 102 being exposed atthe bottom surface of each of the plurality of third trenches TR3. Next,a second electrode layer 176 may be formed to fill respective remainingspaces of the plurality of indent regions IND and the plurality of thirdtrenches TR3.

In the plurality of capacitors 170, the plurality of first electrodelayers 172 and the second electrode layer 176 may each include a metalfilm, a conductive metal oxide film, a conductive metal nitride film, aconductive metal oxynitride film, or a combination thereof. In anexample embodiment, the plurality of first electrode layers 172 and thesecond electrode layer 176 may each include Ti, Ti oxide, Ti nitride, Tioxynitride, Co, Co oxide, Co nitride, Co oxynitride, Nb, Nb oxide, Nbnitride, Nb oxynitride, Sn, Sn oxide, Sn nitride, Sn oxynitride, or acombination thereof. For example, the plurality of first electrodelayers 172 and the second electrode layer 176 may each include TiN, CoN,NbN, SnO₂, or a combination thereof. The dielectric film 174 may includea high-k film. For example, the dielectric film 174 may include HfO₂,ZrO₂, Al₂O₃, La₂O₃, Ta₂O₃, Nb₂O₅, CeO₂, TiO₂, GeO₂, or a combinationthereof.

According to the method of manufacturing the integrated circuit device100, described with reference to FIGS. 2A to 8C, by using asingle-crystal Si film as the channel region CH of the integratedcircuit device 100, control of leakage current in the channel region CHmay be enhanced. In addition, in selectively removing the plurality ofsacrificial films SL from the mold pattern MP including the plurality ofsemiconductor films 110, which include Si films, and the plurality ofsacrificial films SL, which include SiGe films, the etchant compositionaccording to an example embodiment is used. Therefore, even when each ofthe plurality of sacrificial films SL has a relatively low Ge content ofabout 10 at% to about 20 at%, e.g., a Ge content of about 15 at% (toprevent dislocation due to lattice mismatch in the plurality ofsemiconductor films 110 including single-crystal Si films), theplurality of sacrificial films SL may be removed at high etchselectivity with respect to the plurality of semiconductor films 110including single-crystal Si films. Therefore, the reliability of theintegrated circuit device 100 may improve.

By way of summation and review, a technique for securing the reliabilityof a 3-dimensional semiconductor memory device, in which a silicon (Si)film is used as a channel region, is desired.

As described above, an example embodiment may provide an etchantcomposition that may provide a high etch selectivity of a silicongermanium (SiGe) film with respect to a silicon (Si) film.

An example embodiment may provide a method of manufacturing anintegrated circuit device, the method allowing the reliability of anintegrated circuit device to be improved by removing an SiGe film withhigh etch selectivity to an Si film during the process of manufacturinga 3-dimensional semiconductor memory device.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. An etchant composition for etching a silicon germanium film, the etchant composition comprising: about 5 wt% to about 14 wt% of an oxidant, based on a total weight of the etchant composition; about 0.01 wt% to about 5 wt% of a fluorine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 5 wt% of an amine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 1 wt% of an alcohol compound having a hydrophilic head and a hydrophobic tail, based on the total weight of the etchant composition; about 60 wt% to about 90 wt% of an organic solvent, based on the total weight of the etchant composition; and a balance of water.
 2. The etchant composition as claimed in claim 1, wherein the oxidant includes a C1-C6 carboxylic acid compound, a C1-C6 peroxyacid compound, or a combination thereof.
 3. The etchant composition as claimed in claim 1, wherein the fluorine compound includes hydrofluoric acid (HF), sodium fluoride (NaF), potassium fluoride (KF), aluminum fluoride (AlF₂), lithium fluoride (LiF₄), calcium fluoride (CaF₃), sodium hydrogen hexafluoride (NaHF₆), ammonium fluoride (NH₄F), ammonium difluoride (NH₄HF₂), tetramethylammonium fluoride ((CH₃)₄NF), potassium bifluoride (KHF₂), fluoroboric acid (HBF₄), ammonium tetrafluoroborate (NH₄BF₄), potassium fluoroborate (KBF₄), hexafluorosilicic acid (H₂SiF₆), or a combination thereof.
 4. The etchant composition as claimed in claim 1, wherein the amine compound is selected from a C1-C8 aliphatic amine compound and a 5- to 8-membered cyclic amine.
 5. The etchant composition as claimed in claim 1, wherein the alcohol compound includes a polyhydric alcohol having a C8-C16 normal alkyl group and at least two hydroxyl groups.
 6. The etchant composition as claimed in claim 1, wherein the organic solvent includes a C1-C5 carboxylic acid compound.
 7. The etchant composition as claimed in claim 1, further comprising about 0.01 wt% to about 5 wt% of a catalyst, based on the total weight of the etchant composition, wherein the catalyst includes sulfuric acid or methanesulfonic acid.
 8. A method of manufacturing an integrated circuit device, the method comprising: forming, on a substrate, a structure in which a plurality of silicon films and a plurality of silicon germanium films are alternately stacked; and selectively removing the plurality of silicon germanium films from among the plurality of silicon films by using an etchant composition, wherein the etchant composition includes: about 5 wt% to about 14 wt% of an oxidant, based on a total weight of the etchant composition; about 0.01 wt% to about 5 wt% of a fluorine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 5 wt% of an amine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 1 wt% of an alcohol compound having a hydrophilic head and a hydrophobic tail, based on the total weight of the etchant composition; about 60 wt% to about 90 wt% of an organic solvent, based on the total weight of the etchant composition; and a balance of water.
 9. The method as claimed in claim 8, wherein: in the forming of the structure, each of the plurality of silicon films and the plurality of silicon germanium films is formed by an epitaxial growth process, each of the plurality of silicon films includes a single-crystal silicon film, and a germanium content in each of the plurality of silicon germanium films is in a range of about 10 at% to about 20 at%.
 10. The method as claimed in claim 8, further comprising, after the forming of the structure, forming a silicon nitride film to cover a sidewall of the structure, wherein: the plurality of silicon germanium films are selectively removed from among the silicon nitride film and the plurality of silicon films by using the etchant composition, and after selectively removing the plurality of silicon germanium films, the silicon nitride film and the plurality of silicon films are exposed in spaces from which the plurality of silicon germanium films are removed.
 11. The method as claimed in claim 8, wherein, in the etchant composition, the oxidant includes a C1-C6 carboxylic acid compound, a C1-C6 peroxyacid compound, or a combination thereof.
 12. The method as claimed in claim 8, wherein, in the etchant composition, the fluorine compound includes hydrofluoric acid (HF), sodium fluoride (NaF), potassium fluoride (KF), aluminum fluoride (AlF₂), lithium fluoride (LiF₄), calcium fluoride (CaF₃), sodium hydrogen hexafluoride (NaHF₆), ammonium fluoride (NH₄F), ammonium difluoride (NH₄HF₂), tetramethylammonium fluoride ((CH₃)₄NF), potassium bifluoride (KHF₂), fluoroboric acid (HBF₄), ammonium tetrafluoroborate (NH₄BF₄), potassium fluoroborate (KBF₄), hexafluorosilicic acid (H₂SiF₆), or a combination thereof.
 13. The method as claimed in claim 8, wherein, in the etchant composition, the amine compound is selected from a C1-C8 aliphatic amine compound and a 5- to 8-membered cyclic amine.
 14. The method as claimed in claim 8, wherein, in the etchant composition, the alcohol compound includes a polyhydric alcohol having a C8-C16 normal alkyl group and at least two hydroxyl groups.
 15. The method as claimed in claim 8, wherein, in the etchant composition, the organic solvent includes a C1-C5 carboxylic acid compound.
 16. A method of manufacturing an integrated circuit device, the method comprising: forming, on a substrate, a mold layer in which a plurality of silicon films and a plurality of silicon germanium films are alternately stacked; forming an insulating structure to cover a sidewall of the mold layer; forming a mold pattern by forming a trench through anisotropic etching of the plurality of silicon films and the plurality of silicon germanium films, the mold pattern including respective remaining portions of the plurality of silicon films and the plurality of silicon germanium films, which define the trench; and forming a plurality of air gaps by selectively removing, from the mold pattern, the plurality of silicon germanium films through the trench by using an etchant composition, the plurality of air gaps exposing the plurality of silicon films and the insulating structure, wherein the etchant composition includes: about 5 wt% to about 14 wt% of an oxidant, based on a total weight of the etchant composition; about 0.01 wt% to about 5 wt% of a fluorine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 5 wt% of an amine compound, based on the total weight of the etchant composition; about 0.01 wt% to about 1 wt% of an alcohol compound having a hydrophilic head and a hydrophobic tail, based on the total weight of the etchant composition; about 60 wt% to about 90 wt% of an organic solvent, based on the total weight of the etchant composition; and a balance of water.
 17. The method as claimed in claim 16, wherein: each of the plurality of silicon films includes a single-crystal silicon film, and a germanium content in each of the plurality of silicon germanium films is selected from a range of about 10 at% to about 20 at%.
 18. The method as claimed in claim 16, wherein: the insulating structure includes a silicon nitride film contacting a sidewall of each of the plurality of silicon films and the plurality of silicon germanium films, and in the forming of the plurality of air gaps, the silicon nitride film is exposed by the plurality of air gaps.
 19. The method as claimed in claim 16, wherein, in the etchant composition, the oxidant includes peracetic acid, performic acid, acetic acid, formic acid, propionic acid, or a combination thereof, the fluorine compound includes hydrofluoric acid (HF), the amine compound includes a C1-C8 aliphatic polyamine, the alcohol compound includes a C8-C16 alkane-1,2-diol, and the organic solvent includes acetic acid.
 20. The method as claimed in claim 16, wherein: the etchant composition further includes about 0.01 wt% to about 5 wt% of a catalyst, based on the total weight of the etchant composition, and the catalyst includes sulfuric acid or methanesulfonic acid. 